Furnace



T. A. PEEBLES.

FURNACE.

APPLICATION FILED FEB. 20, I918.

Patented May 4, 1920.

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FURNACE.

APPLICATION FILED FEB. 20, 1918.

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T. A. PEEBLES.

FURNACE.

APPLICATION FILED FEB. 20, 19l8.

Patented May 4, 1920.

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Bowl

UN 2 ITEI) STATES PATENT OFFICE.

THOMAS A. PEEBLES, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO DARWIN S. WOLCOTT, TRUSTEE, OF SEW'IQKLEY, PENNSYLVANIA.

FURNACE.

Specification of Letters Patent.

Patented May 4:, 1920.

Application filed February 20, 1918. Serial No. 218,246.

ments in Furnaces, of which improvements 7 the following is a specification.

The invention described herein relates to.

certain improvements in furnaces for boilers, etc., and has for its obj ect the distribution of air for combustion to different portions of the fuel bed and preheating the air delivered to the point of preliminary combustion and portions adjacent thereto, the preheating being preferably efiected by causing the air to flow through members of the fuel supporting means. is hereinafter more fully described and claimed.

In the accompanying drawings forming a part of this specification, Figure l is a sectional elevation illustrating my improvement as embodied in a construction of furnace and stoking mechanism; Fig. 2 is a sectional plan of a portion of the furnace on a plane indicated by the line II-II, Fig. 1; Fig. 3 is a transverse section on a plane indicated by the line III-III, Fig. 1; certain portions which would show an elevation being omitted; Fig. i is a sectional detail view illustrating a modification; Fig. 5 is a sectional detail view, the plane of section being'indicated by the line V-V, Fig. 1, and Fig. 6 is a detail view showing the construction and arrangement of the filling piece intermediate the hollow bars.

In the construction shown the fuel is fed by any suitable means onto and across the forehearth and onto the front end of the main fuel supporting surface consisting of relatively movable members. struction shown these members consist of a series of hollow bars 1 and a series of T-' shaped bars 2 alternating with the hollow bars and adapted to be reciprocated, as described and shown in Figs. 1 and 3, and of the general type shown'in an application filed August 8rd, 1917 Serial Number 1842M. As described and claimed in said application, the hollow bars are spaced such a distance apart that the webs of theT- shaped bars, which are supported by the hollow bars, will project down between ad- The invention In the. con

jacent hollow bars while the heads of the T- shaped bars are made of such widths as to bridge or extend across the spaces between the bars 1; and the adjacent faces of the bars of the two series are so grooved or otherwise constructed as to permit of the free flow of air between the bars and into the The front ends of the two series of bars project under the forehearth which is perforated as is frequently the practice, for the passage of air into the overlying fuel. In the construction shown, provision is made for reciprocating the T-shaped bars, as for example, by oscillating levers having their upper ends engaging the T-shaped bars. The hollow bars are supported at or adjacent to their rear ends by a fianged'plate 3 extending transversely of the furnace and at intermediate points by the partition plates 4, 5 and 6, which divide the space under the fuel supporting members into a plurality of transverse compartments or chambers to suit requirements regarding the distribution of air to different portions of the fuel bed.

The hollow grate bars which are employed for heating the air prior to its passing into the fuel as hereinafter described, are in communication at points adjacent to their rear or discharge ends with an air supply conduit 7 adapted to be connected with a fan or other air compressing means. The conduit is adapted to communicate with the compartments under the fuel supporting members and to that end it preferably extends through the compartments and is constructed with an inverted V-shaped top so that ashes, etc, passing through the fuel supporting surface will slide down to the bottoms of the compartments. In order that the flow of air from the compartments between the grate bars into the fuel bed may be controlled to suit the conditions at different points of the fuel bed, provision is made for the independent regulation of the flow of air into each chamber from the supply conduit. 1

In the construction shown herein, connection between the conduit and the several compartments is formed by openings in the side walls of the conduit and the flow of air through such openings is controlled by valves 8 adapted to be shifted by handles 9 extending through the side walls of the furnace as shown in Figs. 2 and3. Communication between the air conduit and the inlet ports of the hollow bars is formed by a distributing chamber 10 extending transversely of the members forming the fuel support.

The flow of air into the distributing chamber is controlled by a suitable valve mechanism such for example as that shown, consisting of a pivotally mounted damper 11 arranged across the conduit and adapted to be shifted by a handle 13 extending through the side wall of the furnace as shown in Fig. 2. In order to prevent the air from escaping from the distributing chamber through the spaces between adjacent bars, filling pieces 14.- are arranged between the hollow bars, said filling pieces being provided with ribs along their peripheries adapted to contact with the side walls of the hollow bars and extending forwardly beyond the front wall of the distributing chamber as clearly shown in Figs. 1, 2, '5 and 6.

The air enters the hollow bars from the' distributing chamber, flows forwardly and passes through ports 15 in the undersides of the hollow bars into the first compartment underlying the forehearth and the front portions of the grate bars where initial combustion occurs. From this compartment, the heated air passes up into the fuel where initial combustion is taking place. If the damper in the partition 4 is closed, all the air flowing through the hollow bars will pass directly into the fuel at the front of the furnace but by opening the dampers in one or more of the compartments, a portion of the air may be directed through other portions of the bed of fuel.

As is well known to those skilled in the art, combustion of fuel is promoted by heating the air supplied for that purpose and this end is attained in improvements described herein, as the air flowing through the hollow bars will be highly heated by the time it enters the first compartment from which it passes into that portion of the fuel bed where the greatest benefit can be derived from the use of heated air. As the fuel above the compartments other than the first will be in a high state of combustion, the benefit arising from the use of heated air for the combustion of these highly heated portions of the fuel bed, will not be so great or pronounced as where initial combustion occurs, andhence under ordinary conditions, air will be supplied to the compartments other than the first, directly from the conduit. By suitably adjusting the valves 8, the amount of air and its pressure supplied to different parts of the fuel bed can be regulated in accordance with the condition of the different parts of the fuel bed. The volume of air supplied to the portions of the fuel undergoing initial combustion and the pressure of the air are controlled by the valve 11.

It will be understood that the improvement described and claimed herein can be readily used in combustion with forms or constructions of fuel supporting means other than the specific construction and arrangement herein shown and described. As for example, in Fig. 4c is shown a construction wherein provision is made for the flow of air into movable hollow grate bars 17 in case it should be desirable to substitute such bars for the T-shaped bars shown in Figs. 1 and 3.

It being common in the art to employ perforated fore hearths which support the fuel as it enters the furnace, no claim is made herein to such construction per 80.

I claim herein as my invention:

1. In a furnace the combination of spaced fuel supporting members, a plurality of chambers arranged transverse of and below the fuel supports and adapted to supply air to different portions of the bed of fuel on said supporting members, means for feeding heated air to the chamber underlying the portions of the fuel supporting members on which initial combustion occurs and means for supplying air to the other chambers.

2. In a furnace, the combination of spaced fuel supporting members, a plurality of air chambers arranged transverse of and below different portions of the fuel supporting members, means for supplying air to the respective chambers, means for independently regulating the flow of air to the respective chambers and means for heating the air flowing to the chamber underlying the portion of the fuel supporting members on which initial combustion occurs.

3. In a furnace the combination of spaced fuel supporting members, a plurality of air chambers arranged below different portions of the fuel supporting members, an air supply, means for heatin the air flowing to the chamber underlying t e portions of the fuel supporting members on which initial combustion occurs, and valve controlled means for conducting heated air from said chamber to chambers underlying other portions of the fuel supportin members.

4. In a furnace t e combination of spaced fuel supporting members, a portion at least of said members having passages therein, air supplying means in communication with said passages at points remote from the front ends of the members, a chamber underlying the front portions of the fuel supporting members and connected to said passages at points adjacent to the front portions of the fuel supporting members, whereby air may be heated prior to its passage into the portion of the fuel bed in which initial combustion occurs.

In a furnace the combination of a fuel supporting surface consisting of spaced bars, a portion at least of said bars having passages therein, a plurality of chambers arranged under the fuel supporting surface, air supplying means, a conduit communicating with said air supplying means and communicating with the passages in the fuel supporting surface at points remote from the front portions of said surface, connections from such passages to the chamber underlying the portion of the fuel supporting surface on which initial combustion occurs, and valved connections from the conduit to the other chambers underlying the fuel supporting surface.

6. In a furnace the combination of a wind box having a plurality of compartments, spaced fuel supporting members arranged transversely of the compartments, a portion of said members having longitudinal passages, a conduit communicating with the passages in the fuel supporting members at points adjacent to the rear ends of the fuel supporting members, said fuel supporting members having ports adjacent to their front ends for the flow of air from the bars into the underlying compartment, connections from the conduit to each of the 001m partments and means for regulating the flow of air from the conduit to the respective compartments.

7. In a furnace the combination of a plurality of compartments, spaced fuel supporting members above and transverse of the compartments, alternate members having longitudinal passages, an air conduit extending through the compartments and having valved connections therewith, and having a valved connection with the passages in the fuel supporting members, said members having ports adjacent to their front ends for the flow of air into theunderlying compartment.

In testimony whereof, I have hereunto set my hand.

THOMAS A. PEEBLES. 

